a. Field of the Invention
The present invention pertains to communication devices and specifically to serial communications devices with scramblers and de-scramblers.
b. Description of the Background
High speed serial communications protocols are operating at higher and higher speeds. It may become very difficult for test equipment to effectively test a serial communications device when the device is operating at full speed for a number of reasons, including the difficulty of providing an input stream and analyzing the stream at a speed that approaches the normal operating speed of the serial interface.
In order to test a device, it is sometimes preferred to send a seemingly random sequence of characters. In order for a test to be duplicated, it is sometimes preferred that the seemingly random sequence of characters be repeatable. The conflicting requirements of randomness plus being repeatable pose some problems to the testing engineer. One solution is to prepare a predetermined random sequence of characters that may be sequentially sent over the interface. In such a solution, a large amount of data may need to be accessed, transferred, and analyzed in order to exercise a serial interface.
It would be advantageous to provide a system and method for testing a serial interface wherein a repeatable, yet apparently random sequence of information may be passed across the serial interface in a simple and easy fashion. It would be further advantageous to provide a system and method for testing an interface wherein an apparently random sequence is transferred and compared at the full speed of the interface with as little instrumentation as necessary.